Many types of wrench have been provided for gripping a mechanical element requiring application of torque for rotational movement or holding against rotation. Vise grips, for example, use a pair of jaws with multiple pivot points between the jaws together with a lever arm and over-centre locking arrangement for obtaining a tight grip on an element requiring turning. However, vise grips are sometimes difficult to remove from the article gripped and are limited in the size range of articles for which they are effective.
Multigrips have a wide range of size adjustments, but, for gripping an article, are limited to a simple mechanical advantage resulting from the ratio of the jaw length to the handle length, and a tight grip on the handles is required to maintain sufficient grip on the article.
The present invention aims to provide a wrench which alleviates one or more of the disadvantages of the prior art. Other aims and advantages may hereinafter become apparent.